#autoload

local -a type expl_type_arr rsrc rdst paths_allowed
local -a typearg datasetlist expl mlist
local expl_type

# -e takes an argument which is passed as as the "descr" argument to _wanted
# -p indicates that filesystem paths, not just dataset names, are allowed
# -r1 indicates that we're completing the source of a rename
# -r2 indicates that we're completing the destination of a rename
# -t takes arguments (what kinds of datasets) and can appear multiple times
zparseopts -D -E e:=expl_type_arr p=paths_allowed r1=rsrc r2=rdst t+:=type

[[ -n $type[(r)fs] ]]    && typearg=( filesystem )
[[ -n $type[(r)vol] ]]   && typearg=( $typearg volume )
[[ -n $type[(r)snap] ]]  && typearg=( $typearg snapshot )
[[ -n $type[(r)share] ]]  && typearg=( $typearg share )
if [[ -n $typearg ]]; then
	typearg=( -t ${(j:,:)typearg} )
# We know we're in zfs list if paths_allowed is non-empty.
elif [[ -n $opt_args[-t] && ${#paths_allowed} -gt 0 ]]; then
	typearg=( -t $opt_args[-t] )
fi

if [[ ${#paths_allowed} -gt 0 && $PREFIX == /* ]]; then
	_path_files
	return
fi

if [[ ${#rsrc} -gt 0 ]]; then
	# With the -r option to zfs rename, we can only rename snapshots.  With the
	# -p option, we can only rename filesystems and volumes.
	if [[ -n $words[(r)-r] ]]; then
		typearg=( -t snapshot )
	elif [[ -n $words[(r)-p] ]]; then
		typearg=( -t filesystem,volume )
	elif [[ $implementation == openzfs ]]; then
		typearg=( -t filesystem,snapshot,volume )
	else
		typearg=( -t filesystem,share,snapshot,volume )
	fi
fi

if [[ ${#rdst} -gt 0 ]]; then
	if [[ ${words[CURRENT - 1]} == *@* ]]; then
		# If we're renaming snapshots, there's nothing to complete, so
		# we simply give instructions.  (In non-recursive cases, we
		# could put the name of the snapshotted dataset first, but why
		# bother with the long form?)
		_message -e 'snapshot name (beginning with "@")'
		return
	else
		# The parent dataset must be a filesystem, and can't rename
		# a dataset into another pool.  Plus we hardcode the expl.
		typearg=( -t filesystem -r ${${words[CURRENT - 1]}%%/*} )
		expl_type_arr=( -e "parent dataset" )
	fi
fi

if [[ -n $type[(r)clone] ]]; then
	datasetlist=( ${="$(zfs list -H -o name,origin -t filesystem | awk "\$2 != \"-\" {print \$1}")":#no cloned filesystems available} )
else
	datasetlist=( ${="$(zfs list -H -o name $typearg)":#no datasets available} )
fi

expl_type=${typearg[2,-1]//,/\/}
if [[ -n $type[(r)mtpt] ]]; then
	mlist=( ${="$(zfs list -H -o mountpoint $typearg)":#no mountpoints available} )
	datasetlist=( $datasetlist $mlist )
	expl_type="$expl_type/mountpoint"
fi

if [[ -n $expl_type_arr[2] ]]; then
	expl_type=$expl_type_arr[2]
fi

_wanted dataset expl "$expl_type" _multi_parts "$@" -q / datasetlist
